Besides being four letters long (and ending in the same three letters) what specific and unusual property do these three words share?
BOWS, ROWS, SOWS
Here is the SOLUTION.
They're heteronyms. Each word has multiple meanings, depending on the pronunciation used.
"Bows" can be a verb ("inclines") or a noun ("arrow shooters").
"Rows" can be a verb ("participates in a fight") or a noun ("lined-up groups").
"Sows" can be a verb ("plants seeds") or a noun ("adult female pigs").
NOTE: These three words each have additional meanings, as well.